Blood Vessels Flashcards
What are the three layers of blood vessels?
Tunica Intima (inner)
Tunica Media (middle)
Tunica externa/adventitia (Outer)
What do layers provide the vessel with?
Strength
What is the difference between the Tunica Intima in arteries vs veins?
The Tunica Intima is bigger in Arteries compared to veins so in arteries, the layer is wavy but in veins the layer is smooth
What is the Tunica Media made of?
Smooth Muscle
What do contraction and relaxation of the vessels cause?
Relaxation - Vasodilation
Contraction - Vasoconstriction
What are facts about the Adventitia?
It contains collagen fibers
They serve as the connective tissue anchoring vessel
Some walls are too thick to use diffusion so they have there own blood supply called the vasa vasorum
Where do arteries and Veins carry blood?
Arteries carry blood away from the heart and Veins carry blood toward the heart
Which vessel has thicker walls?
Arteries have the thicker walls to help better withstand the pressure
How do the two types of vessels behave when cut?
Arteries maintain their shape but veins collapse when they are cut
What are the “size levels” of the different blood vessels?
Arteries, Arterioles, Capillaries, Venules, Veins
What are capillaries? What are they for?
They are the bridge between Arteries and Veins that are about the size of a RBC in diameter. They permit an exchange of gases between blood and interstitial fluids
What are fenestrated capillaries?
They are capillaries with pores
What are precapillary sphincters?
They help regulate blood flow through capillaries
How is the blood kept moving through the capillary bed?
The Metarteriole creates a thoroughfare channel that always stays open
Why do some important areas of the body have more than one capillary bed?
More than one arteries supply the area just in case there happens to be a blockage
What do veins have that arteries don’t?
They have Valves (venous valves) to make sure blood flow is in one direction
What can Improper Venous Valve closure cause?
Varicose Veins
Where is most of the blood in vessels kept?
30-35% is kept in the arteries, 65-70% is kept in the veins
Which Heart circuit has more pressure?
The systemic circuit has more pressure than the pulmonary circuit
What does the Brachiocephalic trunk branch into?
The right common carotid artery and the right subclavian artery
What comes from the descending aorta? (Heart only)
The Coronary arteries
What do the common carotids divide into?
Internal and External carotids
What is the carotid sinus
Like the blood police/bouncer for the brain
It sits at the base of the internal carotid artery
What is the path from the Right Subclavian artery down?
Right subclavian > Right axillary > Right brachial > Right radial and ulnar > superficial palm arch > Digital arteries
What is the biggest artery for the brain?
The Basilar Artery
What does the descending aorta split into?
Left and Right common iliac
What are the two sections of the descending aorta?
The Thoracic aorta and the Abdominal aorta
What are the main arteries of the leg?
The Femoral artery (Femur) > Popliteal artery (knee) > Anterior Tibial and Posterior Fibular arteries > Plantar arteries
The Deep Femoral artery
What do temporal and maxillary veins drain into?
External jugular vein
Where do facial veins drain into?
Internal jugular veins
Where do vessels in neck drain into?
External jugular vein then into the subclavian vein
What vein is used most commonly to draw blood?
The median cubical vein
Which vein in the lower leg usually has a wavy appearance?
The Great Saphenous
What does the hepatic system do?
It brings blood from the digestive system to the liver before it goes to the heart to be reoxygenated
